Nano-Diamond Coated Cutting Tools: Modeling Tool Geometry Effects

本研究的目的是通过对刀具几何效应的基础研究，更新纳米金刚石涂层刀具的设计。超硬，良好的附着力和光滑的纳米金刚石涂层有可能彻底改变涂层刀具技术，以满足现代加工的挑战。然而，由于金刚石沉积和切削过程的交织效应，刀具几何形状如何影响金刚石涂层刀具在机械加工中的性能是最不了解的。该研究方法包括实验研究和计算建模的沉积残余应力，纳米压痕，涂层-基体的附着力，使用散装压痕，切削应力和温度的金刚石涂层工具继承与涂层属性，使用二维正交加工，和涂层工具故障，使用三维加工。这些主题将以可变刀具几何形状为中心进行综合研究，包括微观和宏观特征，如切削刃半径和刀尖角。刀具几何形状、涂层分层和刀具寿命之间的联系，以及涂层刀具从沉积到加工的热机械演化，将指导纳米金刚石涂层刀具的优化设计，这项研究将通过刀具技术的进步直接造福社会，从而增强国内制造商在全球竞争中的地位。与工具制造商，金刚石涂层机，和汽车行业的工具用户合作，这项研究提供了渠道，为特定的加工任务量身定制的纳米金刚石涂层工具的有效设计。此外，金刚石涂层刀具在机械加工中的行为的新知识将转化为纳米金刚石涂层钻头和其他复杂形状刀具的开发，这是制造业急需的。这项研究的进一步社会影响包括由代表性不足的学生进行的本科生研究，他们还将协调广泛的研究传播。此外，本研究将通过两年制大学课程的机床技术学生参与项目，向社区推广。

The objective of this research is to renovate the designs of nanostructured diamond (nano-diamond) coated cutting tools through fundamental studies of tool geometry effects. Ultrahard, well-adherent and smooth nano-diamond coatings have a potential to revolutionize the coated tooling technology to meet modern machining challenges. How the tool geometry affects diamond coated tool performance in machining, however, is least understood because of the interwoven effects of both the diamond deposition and cutting processes. The research approach includes experimental investigations and computational modeling of deposition residual stresses using nanoindentation, coating-substrate adhesion using bulk indentation, cutting stresses and temperatures of diamond coated tools inherited with coating attributes using two-dimensional orthogonal machining, and coating tool failures using three-dimensional machining. The subjects will be integratively studied centered on variable tool geometry including micro- and macro-features such as the cutting edge radius and nose angle. The connections between the tool geometry, coating delamination and tool life, correlated with the thermomechanical evolution of the coated tools from deposition to machining, will guide optimal designs of nano-diamond coated tools.This research will directly benefit society by advancement of cutting tool technology that will strengthen the national manufacturers in global competition. Collaborated with a tool maker, a diamond coater, and tool users from automotive industry, this research offers channels for efficient designs of nano-diamond coated tools tailored to specific machining tasks. In addition, the new knowledge of diamond coating tool behavior in machining will be transformed into development of nano-diamond coated drills and other complex-shape tooling, which are critically needed in the manufacturing industry. Further societal impacts of this research include undergraduate research by underrepresented-group students, who will also coordinate broad research dissemination. In addition, this research will reach out to the community through project participation by machine tool technology students from two-year college programs.